Individual hard drives are becoming ridiculously cheap, but as they pile up to create massive storage arrays the cost gets pretty massive as well. What's your best bet for storing huge amounts of data affordably?

There are tons of storage options, directly attached and on the network, so when you want to store a lot of data the right solution can often depend on specific needs. Still, it's better to keep this general-purpose so we're coming up with solutions people can adapt to their needs. With that in mind, we'll keep this challenge simple with some target specifications:

6TB of usable storage (i.e. 4x2TB hard drives in a RAID 5 array)

Connectivity must be faster than USB 2.0

Bonus points for network connectivity

How would you do it? Build it? Use an existing solution? Do something unusual and creative? Let's hear your storage solutions in the comments.